1. Field of the Invention
The present invention relates to a camera of an automatically focusing type and, in particular, to a camera which is provided with an alarm function to give an alarm when the distance from the photographic lens of the camera to an object is beyond the range of the photographable distance.
2. Description of the Related Art
Conventionally, as a camera having a distance alarm function, there have been known cameras which are provided with a near distance alarm function to give the alarm that the photographic lens of the camera is too near to an object, and cameras with a remote distance alarm function to give the alarm that the object is too remote for the strobe light to reach.
In either of the above-mentioned conventional cameras, the photographable distance range is set in a fixed manner, for example, it is set using as a full-aperture condition, so that a satisfactory image quality can be obtained even under the worst conditions. In other words, in the conventional cameras, even when the distance to the object can be a photographable distance according to photographic conditions, since the value of photographable distance range is set fixedly, an alarm is given uniformly when the distance to the object is out of the set distance range to make the photographing impossible, so that the user of the camera will lose the chance of photographing. This is a problem to be solved in the conventional cameras.
Also, in the conventional camera of an automatically focusing type which is provided with a strobe, the strobe is arranged to automatically emit light when the brightness of field is equal to or lower than a predetermined level, and also in the automatic light emission from the strobe if the distance to the object is out of the range of distance that the strobe light can reach, then an alarm is given uniformly to thereby make it impossible to focus on the object.
As in the above-mentioned conventional auto-focusing cameras, if the distance range for uniform focusing in the strobe automatic light emission is limited to the distance range that the strobe light can reach, then an alarm is given to thereby make the focusing impossible even when there is available the external light equal to the strobe light, for example, in a day light synchro-flash photography in which the strobe is forced to give forth light in the backlight. Also, even when there is available the image surface light amount to such a degree that a practicable image quality can be obtained due to the latitude of a film, the alarm is given similarly to thereby prevent the focusing, so that the photographing is made impossible or the photographing is performed out of focus.